package com.hmdp.utils;

import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.core.lang.UUID;
import cn.hutool.core.util.BooleanUtil;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.data.redis.core.script.RedisScript;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

/**
 * @Description:
 * @Author: wangshuo
 * @Date: 2024/7/5 16:36
 */
public class SimpleRedisLock implements ILock {

    private String name;
    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString(true) + "-";

    public static final DefaultRedisScript<Long> UNLOCK_SCRIPT;

    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    @Override
    public boolean tryLock(long timeoutSec) {
        // 获取线程标识 value
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        //获取锁
        String key = KEY_PREFIX + name;
        Boolean success = stringRedisTemplate.opsForValue().setIfAbsent(key, String.valueOf(threadId), timeoutSec, TimeUnit.SECONDS);

        return BooleanUtil.isTrue(success);
    }

    /**
     * 使用lua脚本释放锁
     */
    public void unlock() {
        // 调用lua脚本
        stringRedisTemplate.execute(UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX + Thread.currentThread().getId());
    }

    /**
     * 释放锁
     */
/*    @Override
    public void unlock() {
        String key = KEY_PREFIX + name;
        // 获取线程标识
        String threadId = ID_PREFIX + Thread.currentThread().getId();
        //获取锁中的标识

        String id = stringRedisTemplate.opsForValue().get(key);
        // 判断是否一致
        if (threadId.equals(id)) {
            stringRedisTemplate.delete(key);
        }
    }
    */

}
